People can be classified as attracted to both sexes, to men, to women, or to neither sex, and also as instrumental-expressive, instrumental, expressive, or non-instrumental-expressive. The two hypotheses tested herein are, on the one hand, the relative independence between these two typologies and, on the other, the close relation between sexual dimorphism and sexual attraction, in contrast to the relative independence between sexual dimorphism and the instrumental and expressive domains. A total of 503 university students (284 women and 219 men) completed two assessment instruments: The Sexual Attraction Questionnaire (SAQ) and the Bem Sex Role Inventory (BSRI, 12 items). Analysis of contingency tables was performed. The results provide empirical support for the hypothesis of independence of the two typologies, solid support for the relation between sexual dimorphism and sexual attraction, and clear support for the independence between the gender domains and sexual dimorphism. The implications of these data for the different outlooks concerning the relations between sex and gender are established.

Sexual attraction is an essential part of sex, just as the instrumental and expressive traits are the mainstay of gender. Various hypotheses concerning the dimensionality and independence versus dependence/overlapping of these core entities were tested. A group of 423 university students completed the Sexual Attraction Questionnaire (SAQ; Fernández, Quiroga, & Rodríguez, 2006) and the 12-item Bem Sex Role Inventory (BSRI; Bem, 1974). Internal consistency and factor analyses (PAF) were conducted. The results support the dimensionality established for the SAQ and reveal some psychometric and conceptual weaknesses of the 12-item BSRI. The results also support the independence of the two cores: sexual attraction and the instrumental and expressive traits. The logical implications for the different viewpoints of the relations between sex and gender are discussed.

The Sexual Attraction Questionnaire (SAQ) was designed to measure sexual attraction (Fernández, Quiroga, & Rodríguez, 2006), because the current questionnaires were considered inadequate. The purpose of this research was to test whether the SAQ factors remain meaningful after several years (stability) and whether the Italian version is equivalent to the Spanish one (consistency). Three groups of university students participated: two from Spain (n = 182 and 255, respectively) and one from Italy (n = 293). The Spanish groups were tested with a 7-year interval (2001-2008). The Italian group was tested in 2008. The main hypotheses were to test, across time interval and countries: (a) factor congruence, (b) predictive power of factors (proportion of variance accounted for), and (c) scale reliability. Sexual attraction typology also was analyzed, within and between countries, to test the validity of the underlying theoretical model. The results obtained show that the SAQ factor structure remains the same, the resulting factors have high predictive power, and the SAQ scales are highly reliable. Sexual dimorphism and sexual attraction typology are highly associated, thus validating the underlying theoretical model.